Paul J. Barreira, director of the Massachusetts university’s health services, told the student newspaper that the rise in cases is worrying.

“I’m actually more concerned now than I was during any time of the outbreak,” Barreira told The Harvard Crimson. “I’m desperate to get students to take seriously that they shouldn’t be infecting one another.”

Mumps is spreading so fast, it could affect the university’s May 26 commencement, he said.

“If there’s a spike this week, that means those students expose others, so now we’re looking at a potential serious interruption to commencement for students,” Barreira told the student newspaper. “Students will get infected and then go into isolation.”